Refrigerating apparatus



L. E. CARSON REFRIGERATING APPARATUS July 3l, 1951 4 Sheets-Sheet 1 Filed Jan. 18, 1947 INVENTOR. /gz/fe/zre i (ansa/7 By L1-y, n.4/

July 31, 1951 l.. E. CARSON 2,562,446

REFRIGERATING APPARATUS '5 Filed Jan. 18, 1947 4 Sheets-Sheet 2 l INVENTOR.

July 31, 1951 L. E. CARSON 2,562,446

REFRIGERATING APPARATUS Filed Jan. 18, 1947 4.Sheet-s-Sheet 5 INVENTOR. l j law/'snaai (afn/7 Patented Jul-.y 31%, vi951' UNITED" STATES PATENT OFFICE REFRIGERATING APPARATUS Lawrence Il. Carson, Alhambra; Calif.l s Application January 18, 1947, Serial No. '722,791A

20 Claims.

`'which embodies apparatus and method for auto- 'Kmaticallyfdefrostingfthe' refrigeration coils of a lowy temperature refrigerator while preventing thetransfer of heat generated in the defrosting operation to the low temperature storage com'- partment along an unobstructed path. Means 'comprising' a hooded coil housing' are therein provided to trap the air heated in the area of the coils-during the d'efrostingl operation, while leavingv an open space below the'levelof the coils for the circulationA oi cold air, preferabl'yby rforcedE draft, along'a duct system to the low teinpe'rature storage oon'ipartmeni',v andback to the hooded coilv housing;

TheI instant invention utilizes all ofi the struc:- ture embodied in the invention of the'co-pending application, but, additionally, incorporates one or morehigh temperature storage compartments adapted to be'maintainedata temperature considerably below normall room temperature, but in excess of"th'e"temperature of-the freezingpoint These compartments arel located in the same cabinet a'sfthe low temperature coin'- p'artm'en't, suitable insulation being provided therebetween;

@ne of the objects of the in'stantinventio'n is to" provide means wherebyy the temperature of the high temperature:` c'ompartmentlmay be controlled.

Another object of' the instant invention is to provide-means-whereby' the humidity of the high A,temperature compartment may be controlled'.

Afurther objectof the invention is to provide means whereby`V the temperature and humidity ci the high temperautreY compartment may be 'controlled'by a control of a diverted portion of advantages" of'the invention areprefer'ably ac# complished by providing a Vmediallya'nd longitdinallyf partitioned ductfin juxtaposition to a substantial portieri'E of the wallL area Yof the high temperature compartment, and passing through said;l ductv a portieri'v of Ythel lowtemperature air 2 issuing from lthev hooded coil housing. Dampers are provided which"vv may be manually adjusted tocontrol the amount of air passing into; the

duet,l an`d',`also; to control the'refrigerating eiect of said airl on the high temperature compartiments by blocking kor partially blocking either of thev passages of the duct to divert the air from onepassagef tothe other,- thus Varying the ve;- locity of the duct air and its proximity. to' the compartments to vary' thef re'f-rigeratingl efect. The air issues from the' controlV ductY into the air stream' Apassing from the low temperature compartment to the coil housing. Thus, no portion of the temperaturey and humidity' control air forthe hi'ghtemperatureccmpartment passes through the low' temperature compartment.l

A ysuitable' porous' disc/in; thewall o'f ea'ch ofthe high temperature compartments provides for water vapor communication between theiinterior of." each compartment and the:` diverted"y air stream, thusy enabling a substantial control of the humidity of the inthe compartments;

yOtherv objects -a'ri'dadvantages of the invention willl be appar-entf fIfOI Ithe fOlIOW'rigl dScipi'iO'n taken in conjunction-withv th-'drawings forming partof this speciiieationand in which:`

Figure' 11- is.r a` sectional'view' in side elevation of Va refrigerator embodying the invention;

Figure' 2 i'sf a View in? section taken' along the lines v2'-2fofl Figure 1f;

FigurevB is a' View inE section, partly broken away, takeii-lalonglines3A-e3A and iB-'143B' of Fgre 1 withth'e horizontal duct system por'- tion' being taken along' lines `3A---3A, and with the vertical" duct system portion of' Figure 8 being taken alongllines 3B-13`B;,.

FigureL 411s a viewf insect-ion, partly broken away,.takena1rig lines 4'-:4 of Figure 3;

Figure 5 a view insection'talien alonglins -L of'Fig'ure 4; showing'oneof the control areas ofthe temperature and humidity' control duct-Q Fig-ure 61v anehlar'd View in Section taken along l' lines l off Figure "-43 showing ofieof the operating controls fofrf thev dampers ofVv the tem"- ,per'ature andhumidity control ductii Figure 9 is l aff' ghost View in perspective off4 the hoddedcoilfhousing-embodied in the: refrigerator;

Figure 10E is a View'4 in l perspectivesl'iowi'ng'A the reirigerator boi: in ghost'cutline', and thel con'- 3 figuration of the secondary duct system in solid outline; and

Figure 11 is a schematic view showing the positioned relationship between the various compartments of the apparatus.

Referring to the drawings for more specic details of the invention, the refrigerator is comprised of a storage assembly, a duct assembly, and a hooded coil housing, indicated generally at l0, I2 and I4, respectively. Each wall of the storage assembly is comprised of an inner shell 6, an outer shell I8, and a substantial thickness of insulating material I9, such as glass Wool, therebetween. An insulating partition wall is shown as separating a low temperature storage compartment 22 from an auxiliary high temperature storage compartment 24 therebeneath, while another insulating partition wall 26 separates the compartment 22 from a utility high temperature storage compartment 28 located to one side thereof and. at substantially the same height in the assembly7 I0. A thin partition wall v21 shown in Figure 4 separates the compartment 28 from another high temperature storage compartment 29 located therebeneath. Access to the compartment 22 is had through a door 30 located in the top of the assembly and pivotally secured thereto by hinges 32, while access to the -auxiliary compartment is had through a door 34 in the front wall of the assembly I0. A door '36 secured to said front wall by hinges 38 provides access to the utility compartments 28 and 29.

The compartment 22 has a floor 40, and above :said floor, in spaced relation therewith, is a partition 4I equal in area to said oor, said partition having an imperforate portion 43 and a portion 44 having a plurality of spaced apertures 45 providing for communication between the space between the floor 40 and partition 4I and the chamber 22 thereabove. A baffle 41 separates the imperforate portion 43 of the partition 4| from the Vperforated portion 44 of said partition, said baille extending transversely of the chamber 22, as indicated in Figures 1 and 2.

The rear wall of the storage assembly adjacent the low temperature compartment 22 contains a pair of spaced apart vertical ducts 46 and 48, duct 46 having an inlet 50, communicating with the chamber 22 above the partition 4|, and an outlet 52 communicating with the duct assembly I2, and duct 48 having an outlet 54, communicating with the chamber 22 above the parti- ;.tion 4I and with the space between the floor ,40;Y and the partition 4|,Yand an inlet 56. Also contained within the rear wall of the storage assembly adjacent the utility compartment 28 is a duct mouth 58 having a baffle 60 extending downwardly from the roof thereof, a baiile 62 Vspaced therefrom extending upwardly from the `floor thereof, and a rubber damper 64, extending the height of the duct mouth, having one lLedge secured to the duct wall, as by studs 68 and having the other edge secured to a control rlever 68 slidable in the wall of chamber 28.

Communicating with the duct mouth 58 is a duct 10 divided, not necessarily centrally, to form the side wall of compartment 28; section 10C,

extending downwardly from section 10B to section 10D, located along the side wall of compartment 29; section 10E, extending horizontally along the rear wall of compartment 29 and compartment 24, located below the low temperature compartment 22; and section 10F, extending from section 10E toward the housing I4 and having a mouth 13 communicating with the duct 98, hereinafter described. An interconnecting duct 11 is provided for communication between the portions 10A and 10E of duct 10, as shown in Figure 3, said duct passing into portion 10A at the venturi 15.

Partially sheathed rubber dampers 18 and 80 located centrally of the duct section 10A in normal alignment with the duct partition 12, as shown in Figures 4 and 5, are pivotably supported on rods 82 having looped crank arms 84 adapted to be engaged by crank arm 85 of rods 88 journalled for support in trunnions secured within the wall of the assembly, as shown in Figure 6. The rods 88 are adapted to be pivoted by control knobs 9| inset in the jamb of the door 36 to con.- trol the dampers 18 and 80. l

The portion 10A of duct 10 to the rear of compartment 28 is separated from compartment 28 by an insulation wall 92, as indicated in Figures 2 and 4, while the portion 10B of duct 10 above the damper 18 is separated from compartment 28 by a thin insulation wall 93 of varied thickness, said wall 93, as indicated in Figure 3, being of greatest thickness adjacent the upper end of the duct section 10B and of least thickness at a point immediately above the damper 18.

Porous discs 94 and 96 inserted in the walls of compartments 28 and 29 provide for water vapor communication with the duct sections 10C and D, respectively. These discs are provided to control the humidity within the compartments 28 and 29, as will hereinafter appear.

The duct assembly I2 comprises insulation walls similar in type to those of the storage assembly I0 and is secured to the storage assembly so that the outlet 52 of duct 46 and the inlet 56 of duct 48 are in communication, respectively, with spaced apart vertical ducts 98 and |00 within the duct assembly I2. The duct 98 has an outlet |02 and the duct |00 has an inlet |04, both the outlet |02 and the inlet |84 being provided with inwardly extending flanges, as shown.

The hooded coil housing I4, shown in greatest detail in Figure 9, is rectangular in form and comprises side walls |06 and |08, top and bottom walls ||0 and |I2, and front and rear walls ||4 and ||6. In the upper portion of the housing there is supported between the side walls |06 vand |08 a refrigerant coil assembly, indicated generally at I I8, comprising headers |20, a bank of tubes |22, and a plurality of spaced apart parallel fins |24. A metal drainage tray |26 having a pipe drain |28 underlies the coil assembly ||8, and a heater element |21 is located within the housing adjacent the coil assembly. A vertical inner wall |30 and a horizontal inner wall |32, extending from the front wall ||4 and terminating a substantial distance forwardly of -the rear wall I6 denne an air inlet duct having a flanged inlet |34while an L-shaped baille |36 extends from the tray |26 to the inner wall |32 ,above the inlet |34 and from the tray |26 to the bottom wall I I2.

Supported by the wall |06 forwardly and below the coil assembly I|8 is a rotary blower |38 adapted to be driven by a motor located within a housing |40 supported on the outside ofA the housing I4 'on the sidewall |06. The blower comprises an inlet |42, a blower fan, .notshown, and an outlet duct- |44l communicating with` a "flanged outlet'. |46 of .theA housingr I4.

Thehooded coil housing. issecured .to the duct' assembly I2 so that. the flanged .inlet |34 and the flanged outlet |46 of the housing are received, respectively, by the. iiangedoutlet |02 .of the duct 98 andthe flanged inlet |04 .of the duct |00.

The wiring .circuit 4of Figure .8 shows the manner in which the actuating .mechanism of the lrefrigerator is operably interconnected to provide .for a fully automatic cycle ,of operation.. InFig- .ure 8, a compressor motor |48, adapted to .circulate a suitable refrigerantl through the. coil assembly IIB, is connected .across electrical power 'lines .Iiahd |52, while,.in-.shunt therewith, is a motor.|54,..located within the housing. |40 and .adapted to drive thevanof ,blower |3,...and a thermostat switch |56. The heater .element |21 .is .connected from line |50 to .a pole of a: defrost thermostat switchl 6.0:. 'Iheswitches |56 and I6!) are shown in position for :positive low temperature operation of the refrigerator.; and a main .thermostat switch 6-I is providedbetween switch |60 and the compressor motor |48. -Aswitch .|58 actuated by. the door 30 of the low temperature .compartment 22 is also' .provided in the. circuit. -When the. compressor motor .|48 vand the blower motor |54 are in operation, air at a temperature .ofz from 0-13 F. is recirculated .between the hooded coil housing I4 Yand the storage .compart- 'ment 22 in the following manner:A The air, after passing. over the coil assembly |18, passes into 4the blower inlet |42, along the' blower .duct |44, upwardly through duct |00 in .assembly I2, and .downwardly through .duc-t 48 where a portion vof the air stream passes..into the mouth 58 ,of duct 1.0, The remainder of the air `.stream .passes through. the outlet..54 so .that a portion .thereof issuescdirectly into vchamber `22v above vthe .partition 4| and the remainder passes between lioor 40. of said chamber vand the partition .4 I, vsaid lat- .ter .portion .passing .upwardly into the chamber 22 through the apertures 45 in the portion 44 `ef vthe partition 4 I. Due to the increased velocity .zof the air passing through. the .holes 45 and the .consequent enhanced refrigerative effect of said :airt articles. storedin that'part of the chamber 2.2 to the left of .baille 4.1, as viewed in Figures l .and 2, and above the apertures "45 .are given a quick initial freeze, following whichthey may be -removed to .that portion .off chamber .22 to .the "right .of the baille 41 for storage.` The airat .a temperature of .Il-.13 F. passes out ofthe `compartiment .22 through the duct inlet 50, upwardly .through Vduct 46, downwardly through duct .98, 4and through the duct .|34 inthe housing |4 to 'the coil assembly H8. The dotted arrows of Figure l indicate the path of air from .the :blower 138 to the compartment 22 while the solid `.arrows indicate the path'V of the air in passing from the v'compartment 22 to the blower |38.

. 'That .portion of the lair entering. the mouth .58 of #the duct 'I0 maybe controlled in amount by a'manual adjusting of the damper 64 by means of the control lever 68. Normally, a portion of the volume of air which `passes damper 64 passes into the .duct 'I0 on 'each side Yof the .partition v'1.2. The travels within duct sections '10A and 10B falong the upper rear wa-lllof chamber 218 and the upper side 'wallthereo respectively, passes downwardly through sections '10C and 10D along the fside wall of chamber' 29; .andfisfre'directed in scc-f' ltion. 10E along.' thev rear wall offchamberZQ. and

the rear wall. of chamber 24 .toissuefrom a. duct .outlet.|3into the vertical .duct 98 whereit-re.- joins theair stream passing. into the hoodedcoil housing I4. ,v

. The air,.in1 passingthrough theductfill, serves to withdraw heat from4 the compartments 24, .28 and 29 through the thin duct wall, and this heat Iis surrenderedto the .coil |'I-8, It will be noted .further measure o f controlto. regulate the temperatures of either ofthe: compartments 28 .and

29'without affecting the other'compartment.. VThe temperature of compartment 28. is controllable principally by damper '|8. By `rotating .damper 'I8 in a clockwise direction, as viewed in Figure 5,

`all of the moving air induct 1 0 will be .diverted to the right partition I2 away from the wall of compartment 28, thus reducing` therefrigerative effect of the air stream. Upon reaching the pivoted damper 18, the air stream will resume its travel on both sides of the partition 12 by passing through the opening in the partition vacated by the pivoting of the damper. When they damper 'I8 is rotated in a counterclockwise direction, as viewed in Figure 5, the moving air stream is diverted to the left of the partition 1.2, thus increasing the refrigerative effect of theair stream due to the proximity of the air `to the wall of compartment 28 and the increased velocity of the air. After reaching damper 'I8 the vair vstream is redistributed to pass through the `opening of the partition vacated by the damper. It is thus ,seen

Athat a rotation of damper 'I8 in either direction does not effect a change in the rtemperature of A,compartment 29.

. Similarly, the rotation of .damper in either direction does not alect the temperature of compartment 28. When the Adamper 80 is rotated in a clockwise direction, as viewed in Figure 5, the moving .air stream is diverted to the ,left of the partition 'I2 adjacent the. wal-1 of compartment 29 to provide an enhanced cooling of the compartment due to the proximity of the air stream and itsjincreased velocity. When rotated in a `counterclorckwise direction, vthe damper 80 diverts the air stream to the right -of partition l2 to reduce the cooling eiect of the air stream on compartment 29.

Therelative humidity vin compartments 28 and 29 is controlled `by means of the porous discs .'94 and 05 inset in 'the compartment walls to l'ture vcontent passes the porous discs, .a water vapor partial pressure `differential exists .between the compartments 2.8 .and .2 9- .and the duct 1.0. `The water `vapor on theffhigh .pressure or 'compartment side of the discs is diffused throughthe discs into the air stream in duct to lower the relative humidity in the compartments. There is no movement of the air mass in the compartments through the discs, as this water vapor transfer takes place, because the porosity of the discs is such as to prevent any passage of air therethrough.

The tapered insulation 93 between the duct section- 10B and compartment 28 serves to equalize the temperature of the compartment wall adjacent the duct in the temperature control area of damper 18. The insulation 93 is thickest at the upper end of the side wall of compartment 28 where the temperature of the air stream is .at its lowest value in the control area, and the insulation is decreased in thickness toward the damper 18 in approximate proportion to the rise in temperature of the air stream.

As the air stream enters the Venturi throat in the duct 10, the pressure of the stream is decreased in proportion to a velocity increase, said decrease in pressure serving to allow higher Vpressure air from the lower reaches of duct 10,

i. e., section 10E to enter the Venturi throat through the interconnecting duct 11. The air passing through the duct 11 is at a higher temperature than the air in the forepart of duct 10, i. e., section 10A, and, thus, it is seen that the duct 11, the Venturi throat 15, and the tapered insulation 93 serve to equalize the temperature of the compartment walls adjacent the duct 10. In this manner, extremes of temperature between portions of the walls of compartment 28 and portions of the walls of compart- ."z.

ment 29 are prevented, and the possibility of the zero degree air frosting the walls is obviated. A damper, or other control means, may be provided in duct 11 to control the amount of air recycled between duct sections 10E and 10A.

The metering of the air into the secondary duct system 10 by means of the damper control 64 to restrict the diverted or secondary air stream to a comparatively small percentage of the total air stream in the primary duct system, together with the recycling of the air in the secondary duct system by means of duct 11 and venturi 15, insures that the air passing through the temperature and humidity control region, section 10C, of the secondary duct system will be at a temperature of 32 F. or above, corresponding to the desired temperature range of the high temperature storage compartments 28 and 29.

As the aforedescribed operation continues, heat from the circulating air is being continuously given up to the refrigerant within the coil assembly ||8 to lower the temperature of the circulating air, and frost is being continuously formed on the coil assembly in this process.

When the temperature of the air in the low temperature compartment has dropped to a lower limit value, as for example zero degrees F., the main thermostatic switch I 6|, located within the compartment 22 automatically opens in response to the temperature in compartment 22 to disconnect the compressor motor |48 and the blower motor |54 from the power source. When the temperature of compartment 22 rises to approximately 5, the switch |6I closes to actuate the motors |48 and |54. This operation is continuous until the frost formed on the coil II8 is sufficient to restrict the ow of air through the coil. When the air is restricted and the ns |24 of the coil I8 are partially insulated with a lm of frost, .the effect is produced of reducing the refrigeration load on the coil. When the refrigeration load is reduced, the coil temperature is lowered to a point below its normal temperature corresponding to the equivalent temperature of compartment 22. When the coil temperature is thus reduced, the defrost switch |60, located within the housing I4, automatically reverses to disconnect the compressor motor |48 and the blower motor |54 from the power source and to connect heater element |21, also located within the housing I4 adjacent the coil assembly I I8, to said source. When the air in the vicinity of the coil assembly reaches a temperature of approximately 15 F., the thermostat switch |56 opens. The air within the upper portion of housing I4 is continually heated by the heater element |21 until it reaches a temperature of approximately 38 F. in order to completely defrost the coil assembly I|8. As the temperature Aof the air rises and the defrosting operation continues, water falls from the coil assembly IIB, collects in the tray |26, and passes therefrom through the drainpipe |28 to a location, not shown, outside of the housing I4.

AIt will be noted that the warm air, of a tem perature approaching 38 F., within the housing I4, is prevented from entering the storage compartment 22 and the duct 10 or from causing any substantial temperature raising effect in said compartment and duct by virtue of the warm air trap provided in the housing I4 above the blower |38, and the fact that the warm air will have to extend downwardly to the duct |34 in order to pass into the vertical duct 98, for the air mayv not freely pass through the blower |38 into duct |00 when the blower fan is not in operation.V Thus, there will be relatively little heat transfer due to convection between the housing I4 and the ducts 98 and |00. There will be heat transfer by way of conduction, however, between the warm air at 38 F. in the upper portion of the housing I4 and the cold air in ducts 98 and |00, but as the air in these ducts is raised in temperature, it will rise to be trapped in the upper portion of ducts 46 and 48, and will be prevented from passing into the storage compartment 22 by the downwardly ex'- tending bailie-like insulation wall of the assembly |0, and from passing into the duct 10 by the downwardly extending baille 60 in the duct mouth 58. Additionally, it will be noted that the disposition of the low temperature compartment inlet 54 with respect to the secondary duct inlet 58, and, also, the conguration of the heat loop baille system comprising baffles 60 and 62 within the mouth of the secondary duct 10 cooperatively prevent the passage of low temperature air from the low temperature compartment to the high temperature compartment duct system during periods of inactivity of the blower |38, thus preventing the lowering of temperatures of the high temperature compartments below 32 F.

At the completion of the defrosting operation, therefore, the temperature of the still air in compartment 22 is only slightly raised from its temperature previous to the defrosting operation, and the temperature of the still air in the high temperature compartments is not lowered below When the temperature of the air within the housing I4 reaches 38 F., the defrost thermostat switch |60 again automatically reverses to disconnect the heater element |21 and actuate the compressor motor |48. It is to be noted that Vthe thermostat switch |56 is in the open position and 78 the blower motor |54 is not in operation. The

temperature of :the air within the housing I4 drops under the coolingaction of the refrigerant within the coil assembly H8, and, when the temperature of Athe air has dropped from 38 F. to approximately 13 the-thermostat switch |56 closes to actuate vthe blower motor |54 to cause circulation of the air between the housing I4 and the storage compartment .22 yand duct 'I0 along the closed paths heretoforedescribed. When the air again reaches a temperature of approximately zero degrees F., the main thermostat switch I 6| cycles the operation of condenser motor |48 and blower motor |54 until yice is again sufficiently accumulated on the fins |24 to -restrict the flow of air therebetween.

When the door 3U of the low temperature compartment 22 isopened, the switch |58 is opened thereby to disconnect the motors |48 and |54. The closing of the door closes this switch to .reactuate said motors.

While the preferred embodiment of the invention has been shown and described, it is understood that the structure shown is susceptible of modification within the scope of the appended claims. Y

f What I claim as new and desire to secure by Letters Patent is:

V1. In refrigerating apparatus, the combination of a chamber to be refrigerated defined at least partially by relatively thin walls, relatively thick insulation walls spaced routwardly therefrom, a refrigerant coil, means for effecting forced draft circulation of air between said coil and the space between said walls to refrigerate said thin walls, and control means Within said inter-wall space for varying the `refrigeration effect on said thin walls of a specific volume-of air so circulated.

2. In refrigerating apparatus, the combination of a chamber to be refrigerated defined at least partially by relatively thin Walls, relatively thick insulation walls spaced outwardly therefrom, a refrigerant coil, means for effecting forced draft circulation of air between .said coil and the space between said walls to refrigerate said thin walls, means for controlling the volume of air so circulated, and control means within said space for varying the refrigerationv effect on said thin walls of said controlled volume of air.

3. In refrigeratingapparatus, the combination of a chamber to be refrigerated, a refrigerant-coil,

means for passing air in forced draft circulation from the coil over the walls of the chamber to re-A frigerate said walls and thereby said chamber, and means forming a passageway through a wall of .said chamber providing for capillary communication between the atmosphere of said chamber and said circulating air, whereby the humidity of said atmosphere may be controlled by the removal of water vapor from said atmosphere into said circulating air through said passageway.

4. In refrigerating apparatus, the combination of 'a chamber to be refrigerated and a duct system located exteriorly of said chamber and having a wall in common with the chamber, -a refrigerant coil, means for passing air in .forced draft circulation from the coil to the duct system and therethrough to refrigerate the chamber, means to control the input of y-air into the duct system, and other means located ,within said duct system to control the rate -of passage through said duct system of .the input air passed'i-nto said system by said control means and to vary the proximity of the flow of said input air to the wall common to the chamber and the `duct system.

t 5. vIn'refrigqerating apparatus, `ifhacornbination of a chamber to be refrigerated and a duct system Vlocated exteriorly of said chamber and having a wall in common with said chamber, apartitionparallel to said common .Wall to divide .the duct system, a refrigerant coil, means for ,passing air in forced draft circulation from the coil to the duct system and therethrough along both sides of said Apartition to refrigerate the chamber, means to variably control the input of air into thel duct system, and other means located within said duct system to variably control the rate of pas:A sage through a portion of the duct system of the input air passed into said system by said Vcontrol means by diverting airfromone side of said partition to the other side of the partition to vary the refrigerative effect of said air on said cham# ber.

6. In ref'rigeratingr apparatus, the combination of a chamber to be refrigerated and a duct system Vlocated exteriorly ofV said chamber and hav` ing a wall in common with said chamber, a partition parallel to said common wall to divide the duct system, a refrigerant coil, means for passing air in forced draft circulationfrom vthe Acoilfto`v the duct system and therethrough along both sides of said, partition to refrigerate the chamberr means tovariably control theinputof air into the duct system, other means tovariably controlthe rate of passage through a portion of the duct sys-f tem of the input air. passedv into said system by, said control meansby .selectively directing air,` from one side of saidA partition to the other sideof the partition to vary the refrigerativeelfect of said air on said` chamber, .and means forming1 capillary passagewaysin .said common walltd provide forthe control of the humidity yof the air in vthe chamber by allowing for the passage .of waterl vapor from said chamber into ,said duct system. Y Y

7. In refrigerating apparatus, the combinationy of a chamber to be refrigerated and a ductsysf. tem adapted to pass air over the exterior of said chamber .to refrigerate the same, a refrigerant coil, means for, passing-air in forceddraft circula=. tion from the coil to the duct system and there,y through to refrigerate the chamber, ,and baille means at the mouth ,of said ductsystem adapted to prevent the convective movement of air .in-tol and out of the mouth of the'duct systemdue to! stratified temperature variation of the air when said air is not in forced draft circulation.

8. In refrigerating apparatus, the combination of a primary chamber .andat ,leastone secondary chamber to be refrigeratedarefrigerant coil, a duct system for conveying forced draft .air be'- tween said coil and the interior of the primary. chamber, another duct system connected into the first duct vsystem vvand adapted to bypass a portion of the air y.from ,therst-duct system and direct it exteriorly over the walls .ofthe-secondary chamber to refrigerate said chamber, baffle means in the first duct system adapted to lprevent cold air from passing out of the primary chamber and warm air from passing into the primarycham-f` ber when the air in the duct systems is noti'n forced circulation, and baille means in the mouth of the second duct system to prevent the con` vective movement of air into Vand out of the mouth of the duct system due to stratified tem:- perature Variation of the air when rsaid air is not in forced draft circulation.

9. In ref'rigerating apparatus, the 'combination of a chamber to be refrigerated, a partition .adjaw cent to and inwardly spaced from a wall lof'said chamber to provide therewith a passage, said` partition having a perforate and an imperforate portion, a baille extending from said partition to subdivide said chamber, said baffle serving to separate the perforate and imperforate portions of the partition, a refrigerant coil, means for introducing a forced draft air stream therefrom directly into that subdivision of the chamber adjacent the imperforate portion of the partition and into said passage to enter the other subdivision of the chamber through the perforate portion of the partition, and means for passing the air in said chamber back to said coil.

10. In refrigerating apparatus, the combination of a low temperature chamber and at least one high temperature chamber to be refrigerated, a refrigerant coil, means forming a passageway for forced draft circulation of air over said coil, into said low temperature chamber, and back to said coil, and means forming a second passageway communicating with said first passageway and adapted to receive air from said first passageway for circulation over walls forming the exterior of said high temperature chamber.

11. In refrigerating apparatus, the combination of av low temperature chamber and at least one high temperature chamber to be refrigerated, a refrigerant coil, means for causing an air stream to flow across said coil, means for dividing said air stream, means for receiving one portion of said stream and causing it to iiow into and through the interior of said low temperature chamber, means for receiving the other portion of said stream and causing it to flow across the exterior of said high temperature chamber, and means for rejoining said stream portions and for directing the resultant stream to said coil.

12. In refrigerating apparatus, the combination of a low temperature chamber and at least one high temperature chamberto be refrigerated, a refrigerant coil, means for causing an air stream to flow across said coil, means for dividing said air stream, means for receiving one portion of said stream and causing it to flow into and through the interior of said low temperature chamber, means for receiving the other portion of said stream and causing it to ow across the exterior of said high temperature chamber, means for ren joining said stream portions and for directing the resultant stream to said coil, and control means for the receiving means for said other stream portion adapted for the flow control of said other stream portion.

13. In refrigerating apparatus, the combination of a low temperature chamber and at least one high temperature chamber to be refrigerated, a refrigerant coil, means for causing an air stream to flow across said coil, means for dividing said air stream, means for receiving one portion of said stream and causing it to flow into and through the interior of said low temperature chamber, means for receiving the other portion of said stream and causing it to flow across the eX- terior of said high temperature chamber, means for rejoining said stream portions and for ,directing the resultant stream to said coil, control means for receiving means for said other stream portion adapted for the flow control of said other stream portion, and means forming a passageway between the interior of said high temperature chamber and said last mentioned receiving means, said passageway means embodying a plurality of channels of capillary dimensions for the passage out of said chamber and into said other stream portion of water vapor, whereby the humidity of 12 the atmosphere within said high temperature chamber may be controlled.

14. In refrigerating apparatus, the combination of a low temperature and at least one high temperature chamber to be refrigerated, a refrigerant coil, a first passageway including the interior of said low temperature chamber forming a circuit for the flow of air away from and back to said coil, a second passageway defined in part by the outer surface of the walls of said high temperature chamber having an inlet communication with said first passageway between said coil and low temperature chamber and an outlet communication with said first passageway between said low temperature chamber and said coil, and means for causing a refrigerating air stream to flow across said coil and through said passageways.

15. The combination as set forth in claim 14 wherein valvular means are provided in said second passageway to control the amount of air admitted to said second passageway.

16. The combination as set forth in claim 15 wherein said second passageway has at least a portion thereof divided into parallel sections by a longitudinally extending partition and wherein damper means carried by said partition are operable to intercept the air flow on either side of said partition to control the refrigerative effect on said high temperature chamber of the air passing through said second passageway by controlling the proximity of iiow of said air to the wall of said chamber and the velocity of iiow.

17. The combination as set forth in claim 14 wherein said second passageway has at least a portion thereof divided into parallel sections by a longitudinally extending partition and wherein damper means carried by said partition are operable to intercept the air flow on either side of said partition to control the refrigerative effect on said high temperature chamber of the air passing through said second passageway by controlling the proximity of flow of said air to the wall of said chamber and the velocity of flow.

18. In refrigeration apparatus embodying a chamber to be refrigerated comprising thin walls, relatively thick insulation walls spaced outwardly therefrom to define therewith a passageway for refrigerating air, a refrigerant coil, and means for effecting the movement of refrigerating air from said coil and through said passageway, the improvement consisting in providing the thin walls of said chamber with a varying effective insulation thickness to decrease the insulating effect of said walls in the direction of flow of said refrigerating air moving past the exterior surfaces thereof, whereby the interior surface portions of said thin walls will have substantially the same temperature due to the juxtaposition, to the exterior wall surface portions of greater insulative thickness, of air of lower temperatures, and, to the exterior wall surfaces of lesser insulative thickness, of air warmed above said lower temperatures by the reception of heat from the wall surfaces.

19. In refrigerating apparatus, the combination of a chamber to be refrigerated and a duct system located exteriorly of said chamber and having a wall in common with the chamber, said duct system having inlet and outlet portions adjacently disposed, a refrigerant coil, means for passing air in forced draft circulation from the coil to the inlet portion of the .duct system, means for receiving said air from the outlet portion of the duct system and for directing said air to 13. A the coil, another duct interconnecting the inlet and outlet portions of said duct system, and a Venturi-like restriction in the inlet portion of the duct system located at the mouth of said inm terconnecting duct.

20. In refrigerating apparatus, the combination of low and high temperature chambers to be refrigerated, a refrigerant coil, rst duct means forming a communicating circuit between the region of said coil and the interior of said low ternperature chamber, second duct means forming a communicating circuit between the inlet side of said rst circuit and the outlet side of said first circuit, and by-passing said low temperature chamber, said second duct means being defined in part by a relatively thin wall forming a Wall of the high temperature chamber, means for effecting forced draft circulation of air over said coil and through said first and second duct means, and xed baille means located adjacent the inlet 14 of said second duct means operable upon the cessation of said forced draft circulation of air to prevent the passage of low temperature air from said low temperature compartment into said second duct means.

LAWRENCE E. CARSON.

REFERENCES CITED The following references are of record in the le of this patent: l

UNITED STATES PATENTS -Number Name Date 1,979,638 Philipp Nov. 6, 1934 2,180,974 Atchison et al. Nov. 21, 1939 2,285,946 Kalischer June 9, 1942 FOREIGN PATENTS Number Country Date 574,467 Great Britain Jan. 7, 1946 

